Transient behavior and edge effects within a continuous flow parallel plate thermal diffusion cloud chamber were analyzed in terms of thermal conduction, diffusion of water vapor, turbulence of laminar flow, and transient behavior of the conductor and diffusion process. The chamber's dimensions were 1.2 by 33.8 by 150 centimeters; carrier air and aerosol flow were directed along the length. Conduction and diffusion transients, and turbulence occurred at the entrance to the chamber. The authors conclude that it was straightforward to avoid all edge or wall effects and virtually eliminate all perturbations in the continuous flow chamber. Errors due to transients at the inlet to the chamber could be minimized if care was taken to maintain the velocity of the carrier air below the threshold determined by the geometry of the chamber. The equilibration of the carrier air would always be limited by its thermal relaxation. This limit might be partially removed by careful choice of its initial temperature or by use of a separate set of parallel thermal conditioning plates.